Yamaha - Water Pump Repair Kit 6P2-W0078-00-00. Overview. If you run a big Yamaha four stroke long enough, the water pump becomes one of those service items you stay ahead of. The Yamaha Water Pump Repair Kit 6P2-W0078-00-00 includes the core parts needed to rebuild the pump and keep water moving through the engine the way it should. Heat, sand, and everyday running slowly wear down impellers and seals, especially on boats that spend time in saltwater. Installing a full kit during regular servic